Lubricating composition



United States Patent 7 3,098,824 LUBRICATING COMPOSITION Allen F.Millikan, Crystal Lake, and Gifford W. Crosby, River Forest, Ill.,assignors to The Pure Oil Company, Chicago, 111., a corporation of OhioNo Drawing. Original application Nov. 15, 1957, Ser. No. 696,604, nowPatent No. 2,996,532, dated Aug. 15, 1961. Divided and this applicationAug. 24, 1960, Ser. No. 51,494

22 Claims. (Cl. 252-467) This invention relates to lubricatingcompositions contain-ing certain new compounds, their method ofpreparation, and to lubricating oil compositions comprising orcontaining the products thereof, namely, carbonyl-substituted alkylphosphoroamidothioates, particularly phosphorodiamidodithioates.

In copending application Serial Number 630,088, filed December 24, 1956,certain formylalkyl thiophosphate esters are described which areprepared by the reaction of an O, O-diester of a dithiophosphoric acidwith analkena-l such as acrolein, crotonaldehyde, 2-pentenal, etc. Thereaction is carried out in such a manner that instead of condensation,wherein the alkenal serves to provide a linking nucleus between thethiophosphate esters, and the 0x0 group of the aldehyde is removed bythe formation of water, the 0x0 group of the aldehyde reactant isretained in the reaction product to impart unusual properties thereto. I

This invention is directed to the discovery that the re action productof an amine with a phosphorus sulfide can be converted to acarbonylalkyl derivative by reaction with a carbonyl compound having a,B unsaturation. This application is a division of application SerialNumber 696,604, filed November 15, 1957, now US. Patent 2,996,532.

It becomes, therefore, a primary object of this invention to provideoil-soluble, al'koxycarbonylalkyl phosphoroamido esters for use inlubricating oil compositions and a method of preparing same.

Another object of this invention is to provide oil-soluble,carbonyl-substituted phosphorodiamidodithioic esters for use aslubricating oil additives.

An additional object of this invention is to provide a lubricating oiladditive having minimum deposit-forming properties which will enhancethe load-carrying and antiwear properties of a mineral lubricating oil.

A further object of this invention is to provide a lubricating oilcomposition having increased load-carrying and antiwear properties.

According to this invention, it has been found that thecarbonyl-substituted phosphorodia-midodithoic esters of the generalformula,

where R groups are hydrogen or alkyl groups containing 1 to 25 carbonatoms, or are aryl groups, alkylaryl or arylalkyl groups containing from6 to 25 carbon atoms, R is a divalent alkyl radical containing from 1 to25 carbon atoms, and X is selected from the group of hydrogen, alkylgroups (including benzyl, methyl, ethyl, propyl, isopropyl, isobutyl,n-butyl, t-butyl, cyclohexyl, and octyl), and alkoxy, amino, alkylaminoand dialky-l-amino groups, are useful as lubricating oil additives. ingthe foregoing general formula can be formed by the butylamine,di-isobutylamine,

Compounds meet- 3,098,824 Patented July 23, 1963 reaction of aphosphoroamido acid with an unsaturated carbonyl compound. In order thatthe invention may be clearly understood, the general reactants aredescribed and specific examples given.

The phosphorodiamidodithioic acids are prepared by reacting primary orsecondary amines with phosphorus pentasulfide. Useful amines include themethylamines, the ethylamines, aniline, m-benzylaniline,p-benzylaniline, benzylamine, propylamine, isopropylamine,dipropylamine, di-isopropyl'amine, butylamine, di-bu-tylamiue,isoamylamine, isoamyl-amine, p-isopropylaniline, dodecylamine, and thelike. The reaction between primary or secondary amines and P 8 resultsin phosphorodiamidodithioates which may be used as intermediates forpreparing the subject compounds. Mixed diamides are obtained whendia-lkyl amines react with P 5 at about C.

carbonyl compound, of the following formula:

0 R"-C=C C R" R X wherein X is a group as heretofore defined and R" maybe hydrogen, C, to C alkyl groups, including methyl, ethyl, propyl,butyl, isobutyl, pentyl, isopentyl, heiryl, heptyl and octyl, orcombinations thereof. The alpha carbon atom may carry a hydrogen atomand the beta carbon atom may carry one or two alkyl groups, or the alphacarbon atom may carry an alkyl group and the beta carbon atom may carryone or two hydrogen atoms. Since X may be hydrogen, an alkyl group,alkoxy group or amino group, etc., the unsaturated conjugated carbonylcompounds included in this invention are of the class of unsaturatedaldehydes, unsaturated ketones, unsaturated esters, and the unsaturatedamides as general examples. The

n-Butyl acrylate Cyclohexyl acrylate Ethyl acrylate Methyl acrylateOctyl acrylate Acrolein Crotona-ldehyde Beta-methylcrotonaldehydeA-lpha-methylcrotonaldehyde Alpha-methyl-beta-ethylacrolcin Vinyl methylketone Acrylamide Vinyl ethyl ketone N-t-buty-lacrylamide Mesityl oxideN,N-diethylacrylamide Methyl methacrylate Benzyl acrylate From theforegoing illustrations, it is apparent that X in Z-ethylhexyl acrylatethe general formula may also include the met-hoxy, ethoxy, acetoxy,methylamino, ethylamino, dimethylamino and diethyl-amino groups asfurther specific examples.

In order to illustrate the invention, a number of nonlimiting examplesare given:

EXAMPLE I N,N-tri-n-buitylphosphorodiamidodithioic acid was prepared asfollows: One hundred forty-seven g. (1.14 moles) of di-n-butylamine and20.4 g. (0.092 mole) of phosphorus pentasulfide were charged to a 500ml. flask equipment with a mercury-sealed stirrer,thermometer, andreflux condenser. As a reaction mixture was stirred, the temperaturerose to 80 C. spontaneously, and heat supplied by a heating mantlebrought the pot tempertaure to 160-165 C. The system was refluxed forthree hours at this temperature. A white solid product started to format 145 C. and its production appeared to be complete at the end of thisperiod. The product was washed with methanol and dried. Analysis.Calcdfor N, 9.5%; P, 10,5%; S, 21.6%. Found: N, 9.3%; P, 10.3%; S, 19.8%.This product was found to increase the wear rate of a base oil in whichit was blended and was therefore of no value as an antiwear additive.

EXAMPLE II 2-Ethylhexyloxycarbonylethyl Ester ofN,N'-Trin-Butylphosphorodiamidodithioate The product of Example I wasconverted to the Z-ethylhexyloxycarbonylethyl ester by [addition toZ-ethylhexyl acrylate as follows: Twenty g. (0.07 mole) of the N,N'tri-n-butylphosphorodiamidodithioic acid thus prepared, 18 g. (0.10mole) of 2-ethylhexyl acrylate, and 200 ml. of toluene were charged to a500 ml. flask equipped with a mercury-sealed stirrer, thermometer,reflux condenser, and heating mantle. The reaction mixture was stirredand refluxed with a pot temperature of 110 115 C. for twenty-four hours.At the end of this time the solution was completely clear. Under vacuum,the product was stripped with nitrogen to remove solvent. Analysis ofproduct.Calcd for 86% concentrate of C H N O PS N, 5.0 wt. percent; P,5.5 wt. percent; S, 11.4 wt. percent. Found: N, 4.7 wt. percent; P, 5.1wt. percentyS, 8.5 wt. percent.

EXAMPLE III Exactly 142.4 grams (0.59 mole) of di-Z-ethylhexylamine and11.5 g. (0.052 mole) of phosphorus pentasul-fide were charged to a 500ml. flask equipped with heating mantle, motor-driven stirrer, andthermometer. Stirring was applied at once and there was some spontaneousgeneration of heat. Heat was applied by means of the mantle, and thetemperature was raised to 180 C. The temperature was maintained in thatrange for 45 minutes as stirring continued. The product was a clearliquid with an acidity which. indicated that 0.091 mole of acid had beenformed (as against 0.104 mole in theory).

EXAMPLE IV Formylethyl N,N-Tri-2-EthylhexylphosphorodiamidodithioateThree-hundredths mole of the above acid was charged to a 500 ml. flaskequipped with stirrer and a tube for delivering acrolein beneath theliquid surface. Then 18.5 g. (0.34 mole) of acrolein was distilled intothe reaction mixture with stirring. There was some generation of heatand marked darkening of the color. The reaction was complete in an hour.The product was vacuumnitrogen stripped. The product, formylethylN,N-tri-2- ethylhexylphosphorodiamidodithioate, could be expected to bediluted with amine and acrolein polymer since neither of these would becompletely removed by the stripping employed: Analysis.-Calc. for C H NO-PS 5.4 wt.

percent N, .60 wt. percent P, 12.3 wt. percent S. Found: 3.8 wt. peicent N, 1.5 wt. percent P, 2.7 wt. percent S. The S/P/N ratio was1.9/1/2.9; this indicates the excepted amine dilution, as theory wouldbe 2/1/2.

EXAMPLE V N-t-OctylcarbamylethylN,N'-Tri-n-Bwtylphosplzorodiamidodithioate culated for C H N OPS N, 8.8wt. percent; P, 6.5

wt. percent; S, 13.4 wt. percent. Found: N, 7.2 wt. percent; P, 5.6 wt.percent; S, 9.7 wt. percent.

EXAMPLE VI N,N-tricyclohexylphosphorodiamidodithioic acid was preparedas follows: 160.2 g. (0.88 mole) of dicyclohexylamine and 16.5 g. (0.074mole) of P 8 were charged to a 500 ml. flask equipped with thermometer,mechanical stirrer and heating mantle. The reaction mixture was stirredand heated. At about C. a precipitate began to form. This coagulated asthe reaction continued, making stirring very difiicult. The reaction wassuspended temporarily and the supernatant liquid poured off. Thesemisolid lower phase was removed and formed a glass-like solid oncooling. The supernatant liquid was returned to the flask and heated to160 C. with stirring. The solid was pulverized and added at thistemperature as stirring continued. After 15 minutes of reaction, thetwo-phase reaction product was separated while still hot. The lowerphase cooled to a glass-like product, which was pulverized. The acidnumber of this material was 155, near to theoretical forN,N-tricyclohexylpbosphorodiamidodithioic acid, viz., 149.2. Theanalysis of this product was, calculated: 7.5 wt. percent N; 8.3 -wt.percent P; 17.1 wt. percent S.

Found: 5.0 wt. percent N; 8.1 wt. percent P; 14.2 wt. percent S.

EXAMPLE VII Z-Ethylheadyloxycarbonylet/1ylN,NTricyclohexylphosphorodiamidodithioaze The above product was treatedwith a r1.6 molar portion of 2-ethylhexyl 'acrylate at C. in toluenesolution. A very slow reaction took place, and after 4 days a 60% yieldof oil-soluble product was obtained by removal of the liquid phase andsolvent stripping with nitrogen.

Although a number of organic phosphorus compounds have been proposed as'antiwear additives for lubricating oils, the subject class of compoundshas been found to be particularly effective in reducing wear betweenmetal surfaces. In the following table is shown the results of weartests on two kinds of lubricating blends. Base oil A was composedentirely of extract from manufacture of 85 vis., V.I., neutral oil. Baseoil B was composed of 4.8 wt. percent of the above extract, 5.7 wt.percent barium-calcium phenol sulfide-sulfonate detergent add-itive, 6.4wt. percent of acrylic polymer (Acryloid #618) and 83.1 wt. percentvis., 100 V.I., neutral oil.

Wear tests were carried out in triplicate on the fourball E.P. machinein which the average wear-scar diameter was determined after afive-minute test at 1800 rpm, room temperature, 20 kg. load. The subjectcompounds are shown to be effective antiwear compounds compared toamine-P 8 products before conversion to the carbonyl-substituted ester,or to a commercial metal phosphorodithioate. TABLE I.-FOUR-BALL wlg gTESTS ON LUBRIOATING min., 20 kg., 1800 r.p.m., room temp. Phosphorus inblend, 0.10 wt.

percent] Avg. Additive type Additive description Base wear oil scardiam.

Example II. B 0.261 Products of this invention.... E225: gfi i 3:

Example V B 0.272

Example III B 0.311 Amine-P185 products g$gg 2 2 3:232 Example I. A 1 0.546

Commercial P-S.ester Zinc dlalkyl phos- B 0. 278

phorodlthloate. None A 0. 505 do B 0. 280

S01 {fixer phosphorous concentration in blend due to low Wear -scardiameters are best interpreted by comparison with the diameter ofelastic indentation of the balls under the test load. In the case of thetests at 20 kg. load, this diameter is 0.236 mm. and the increase indiameter above this value is an accurate measure of the wear under thetest conditions. The above data show that mineral oil alone, or oilscontaining amine-P 8 products of the phosphorodiamidodit-hioic acidtype, allow relatively high wear rates. Although additives such ascommercial phosphorodithioates and others, including those in base oilB, lower the wear rate substantially from that of mineral oil alone, thesubject compounds give uniformly still lower wear rates in either baseoil.

The foregoing examples describe the preparation and use of severalcarbonyl-substituted phosphoroamidodithioates coming within the broaddefinition of the invention. The species tested as represented byExamples II, IV, V and VII are the preferred embodiments of theinvention.

Other examples include:

N-t-octy1carbamylethyl N,N"-tri-n-propylphosphorodiamidodithioateN-hexylcarbamylethyl N',N"-tri-n-propylp-hosphorodiamidod-ithioateN-diethylcarbamylethyl N,N"-tri-nbutylphosphoro diamidodithioate2-ethylhexyloxycarbonylethyl N,N"-tri-n-butylphosphorodiamidodithioateN-t-octylcarbamylmethyl N,N"-tri-n-propylphosphorodiamidodithioateN-hexylcarbamylmethyl N',N"-tri-isopropylphosphorodiamiidodithioateN-t-octylcarbamylethyl N',N"-tricyclohexylphosphorodiamidodithioateZ-acetylethyl N,N"tri-ethyloctylphosphorodiamidodithioate CarbamylethylN,N"-tri-n-octylphosphorodiamidodithiate N-t-octylcarbamylethylN',N"-tetra-n-octylphosphorodiam idodithioate N-octadecylcarbamylethylN,N"-tetra-n-propylphosphorodiamidodi-thioate N-pentacosylcarbamylethylN,N"-tri-n-propylphosphoroCtia-midodithioate N-octadecylcarbamylethylN',N"-tri-pentacosylphosphorodiamidodithioate N-dodecylcarbamylethylN',N"-tri-heptadecylphosphorodiamidothioate These compounds representthe new and novel compositions of matter of this invention, whetherpresent in a reaction mixture, or in semi-purified or purified form.These new compounds find particular use in lubricating oil compositionsas antiwear agents. When used for this purpose, they may be incorporatedin the oil in amounts ranging from about 0.1 to 5.0 weight percent. Insome applications, less than 0.1 weight percent of thecarbonyl-substituted phosphoroarnidodithioates may be used and in othersmore than 5.0% by weight may be necessary or give better results. Someof these compounds have limited oil solubility but are effective whenused in an amount sufiicient to incorporate about 0.1 weight percent ofphosphorus inthe total composition. For applications where theappearance of the end composition is not important, the compounds ofthis invention may be used as suspensions in the oil-carrier orlubricity agent.

As indicated by the wear tests herein, other addends and ingredients maybe used with the compounds of this invention, including variouslubricating oil addends and d-iiferent kinds of oil-carriers orlubricity agents. Thus, the compounds of this invention may beincorporated in any lubricating oil, cutting oil, extreme pressurelubricant, grease, aqueous-oil suspension, soluble oil and solid rlubricant. The oil-carriers may be various lubricating oil fractions,bright stocks, neutrals or distillates. The addends of this inventionmay be used with synthetic lubricants. The following table gives theproperties of various solvent extracts produced through the manufactureof bright stocks and neutral oils, by way of illustration. This tableincludes the properties of the specific solvent extract, number 19, usedto prepare the formulations tested in Table I.

Ex Sp. gr. Iodine perpertract Crude source Solvent API at VlsJ Vls./Via/210 VI. Pour F. F. numcent cent N0. gravity F. F. F. F. flask fireher QR. sulfur East Texas..." 23,319 4, 750 282 40 d0 15,000 285 +39 30,410 4, 310 310. 1 -1 19, 500 4, 305 313 +27 32, 500 372 +5 25, 000 6,400 355 +27 145, 000 19, 000 616 0 12, 67 2, 514 172. 1 101 1,500 11Pennsylvania 1,365 12 do 1,500

13 Mid'ContL 1,500

41.7 82 200 -61 509 do 50.2 25 East Texas 341 17 do 40.7 16

The materials described in Table II are all prepared or derived throughthe solvent extraction of crude lubricating oils in the manufacture ofrefined oils, i.e., neutrals and bright stocks, as is well known in theart. These materials normally are considered waste products, being theextract phases derived during the solvent extraction and containing apredominance of the aromatic-type constituents as opposed to theparaflinic-type constituents which remain in the raffinate or refinedoil. Solvent extracts are not as resistant to oxidation or sludging asthe corresponding raffinates and have lower viscosity indices and highervis- TABLE III.-BASE OILS API O OO 0C SUS at SUS at Vis. NPA PercentPercent Stable Mineral oil gravity flash, fire, 100 1. 210 F. indexcolor carbon sulfur pour F. residue F.

100 ViS. neutral v 33. 6 405 450 103. 2 39. 7 101 +2 0.00 0. 12 +5 70viS. neutral 36. 6 370 40,5 71. 3 36. 9 111 +1 0. 00 0. l8 0 150 brightStock- 26. 8 570 630 2, 511 156. 0 99 6+ 0. 73 0. 53 5 170 vis. neutral31. 2 420 480 177. 7 45. 2 101 1+ 0. 00 0 cosities than the rafiinates.Accordingly, in using solvent extracts alone to prepare compositionscontaining the addends of this invention, these changes in propertiesmust be taken into consideration as concerns their usefulness as a baseoil.

Solvent extracts are obtained in the following manner, to give anillustration:

In a typical operation, desalted crude oil is first charged to adistillation unit where straight-run gasoline, two grades of naphtha,kerosene, and virgin distillate are taken off, leaving a reduced cruderesidue. The reduced crude is continuously charged to a vacuumdistillation unit where three lubricating oil distillates are taken offas side streams, a light distillate is taken off as overhead, and aresiduum is withdrawn from the bottom of the tower. This residuum ischarged to a propane deasphalting unit wherein propane dissolves thedesirable lubricating oil constituents and leaves the asphalticmaterials. A typical vacuum residuum charge to the propane deasphaltingunit may have an API gravity of 129, viscosity SUS at 210 F. of 1249,flash 585 F., fire 650 F., C.R. of 13.9 weight percent and be black incolor. The deasphalted oil may have an API gravity of 21.5 to 21.8",viscosity SUS at 210 F. of 165-175, NPA color 6-7, flash 575 F., fire640 F., and CR. of 1.7-2.0. The deasphalted oil and various lubricatingoil distillates from the reduced crude are separately subjected tosolvent extraction for the separation of non-aromatic from aromaticconstituents. The refined oil or raflinate from such processes is usedper se or as blending stock and the solvent extract, containingpredominantly aromatic constituents, is the material that may be used asa part of the base oil.

For example, a crude oil from East Texas with an API gravity of 33.1 wastopped to remove such light fractions as gaoline, naphtha, kerosene, anda light lubricating distillate. The vacuum residue was a reduced crudehaving a viscosity of 1251 SUS at 210 F., 2.2 percent sulfur, and an APIgravity of 12.6. After propane deasphalting, the oil had a viscosity of174 SUS at 210 -F., and an API gravity of 21.7. This deasphalted oil wastreated with phenol to produce a rafiinate from which an aviationlubricating oil may be produced. The extract phase from this phenoltreatment, after removal of phenol, is ready for use in preparingcompositions in accordance with this invention.

Other solvents than phenol may be used to obtain the extraction productused in accordance with this invention; for example, liquid sulfurdioxide, nitrobenzene, Chlorex, chlorophenol, trichloroethylene,cresylic acid, pyridine, furfural or the DuoSol solution comprisingliquid propane and cresol may be used. When using phenol, it is pos-Other addends may be used in the compositions of this invention,including lubricity agents, pour depressants, V1. improvers, oxidationinhibitors and the like. Acryloid #618 is the trade name of an acrylicacid polymer useful as a V1. improver. This product is a well-knownaddend having a molecular weight of about 3000, a specific gravity ofabout 0.906 (60 F./ 60 F.), a filash point (C.O.C.) of about 400 F., aviscosity at 100 F. of about 8000 cs., neutralization No. of 0.2, andASTM color of 3. The physical properties of other Acryloid lubricatingoil additives are given in Table IV.

1 When diluted with three parts ofa 400 F. flash mineral oil to decreasethe viscosity and prevent local overheating and cracking.

2 Viscosity pour point.

The detergent-antioxidant that is included in the formulations testedherein is known under the trade name of Paranox 65. Broadly, addends ofthis type comprise about 65 by weight of a phenol sulfide salt and analkaline earth metal sulfonate combination with about 35% mineral oilcarrier. The active ingredients comprise about by weight of a phenolsulfide salt and 20% of the sulfonate. As described in United StatesPatents 2,379,- 241 and 2,761,845, these anti-oxidant-detergents areoilsoluble metal salts of an alkylated hydroxy aryl sulfide mixedalkaline-earth metal petroleum sulfonates. The active ingredients inParanox 65 comprise 65% of a mixture of barium salt of hydroxydiisobutyl phenyl sulfide and calcium petroleum sulfonate With a mineraloil, wherein the proportions of the sulfide salt to sulfonate are 80/20,as before stated. Paranox 65 has the following physical properties:

TABLE V.TYPICA L PHYSICAL PROPERTIES OF LPARAINOX 65 1 Base number.

What is claimed is:

1. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent of acarbonyl-substituted alkyl N,N'- trialkyl phosphorodiamidodithioate ofthe formula wherein R is an alkyl radical having 3 to 25 carbon atoms, Ris of the group consisting of methylene and ethylene, and X is of thegroup consisting of hydrogen, acetyl, amino, diethylamino, hexylamino,t-octylamino, dodecylamino, pentacosylamino, and 2-ethyl bexyloxyradicals.

2. A lubricating composition in accordance with claim 1 in which R is amethylene group.

3. A lubricating composition in accordance with claim 1 in which R is anethylene group.

4. A lubricating composition in accordance with claim 1 in which X ishydrogen.

5. A lubricating composition in accordance wit-h claim 1 in which X isacetyl.

6. A lubricating composition in accordance with claim 1 in which X is aZ-ethylhexyloxy group.

7. A lubricating composition in accordance with claim 1 in which X is anamino group.

8. A lubricating composition in accordance with claim 1 in which X is at-octylamino group.

9. A lubricating composition in accordance with claim 1 in which X is adiethylamino group.

10. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofZ-ethyl-hexyloxycarbonyl-ethyl-NN'- trialkylphosphorodiamidodithioateswherein the alkyl radicals have from 3 to 25 carbon atoms.

11. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofZ-ethylhexyloxycanbonyl-rnethyl-N,N'-

10 trialkylphosphorodiamidodithioates wherein the alkyl radicals havefrom 3 to 25 carbon atoms.

12. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent oflformylethyl-N,N-trialkyl-phosphorodiamidodithioates wherein the alkylradicals have from 3 to 25 carbon atoms.

13. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent offormylmethyl-N,N'-trialkylplrosphorodiami-dodithioates wherein the alkylradicals have [from 3 to 25 carbon atoms.

14. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofN-t-octylcarbamylethyl-N,N'-trialkylphosphorodiamidodithioates whereinthe alkyl radicals have \from 3 to 25 carbon atoms.

15. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to

5.0 weight percent ofN-t-octylcarbamylmethyl-N,N-trialkylphosphorodiamidodithioates whereinthe alkyl radicals have from 3 to 25 carbon atoms.

16. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent of2-ethyl-hexyloxycarbonylethyl-N,N'-tricycloalkylphosphorodiamidodithioates wherein the tricycloalkylradicals have from 3 to 25 carbon atoms.

17. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofZ-ethylhexyloxycanbonylmethyl- N,N'tricycloalkylphosphorodiamidodith-ioaltes wherein the tricycloalkylradicals have from 3 to 25 carbon atoms.

18. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofNat-octylcarbamylmethyl-N,N'-trin-propylphosphorodiamidodithioate.

19. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent of2-ethylhexyloxycarbonylethyl-N,N'-tricyclohexylphosphorodiamidodithioate.

20. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent of Z-ethylhexyloxycarbonylethylN,N'- tri-nbutylphosphorodiamidodithioate.

21. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent offormylethyl-N,N-tri-2-ethylhexylphosphorodiamidodithioate.

22. A lubricating composition comprising a major amount of a minerallubricating oil and about 0.1 to 5.0 weight percent ofN-t-octylcarbamylethylN',N"-trin-butylphosphorodiarnidodithioate.

References Cited in the file of this patent UNITED STATES PATENTS2,146,584 Lipkin Feb. 7, 1939 2,760,957 Adelson Aug. 28, 1956 2,881,201Schrader Apr. 7, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,098,824 July 23, 1963 Allen F. Millikan et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 3, line 22, for "10,596" read 10.5% columns 5 and 6, insert as aheading for the table at the bottom of the page: TABLE II SOURCES ANDPHYSICAL CHARACTERISTICS OF SOLVENT EXTRACTS column 8, line 69, after"mixed" inser t with Signed and sealed this 3rd day of March 1964.

(SEAL) Attest:

ERNEST w SW EDWIN L. REYNOLDS Attesting Officer AC ti g Commissioner ofPatents

1. A LUBRICATING COMPOSITON COMPRISING A MAJOR AMOUNT OF A MATERIAL LUBRICATING OIL AND ABOUT 0.1 TO 5.0 WEIGHT PERRCENT OF A CARBONYL-SUBSTITUTED ALKYL N,NTRIALKYL PHOSPHORODIAMIDODITHIOATE OF THE FORMULA 